/****************************************************************************
**
** Copyright zjzdy
**
** This source code is licensed under under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
****************************************************************************/

// Most of the code here was originally written by Hans Petter Bieker,
// and is included in Qt with the author's permission, and the grateful
// thanks of the Qt team.

#include "tsciicodec_p.h"
namespace zdytool {
	static uchar UnicodeToTSCII(ushort u1, ushort u2, ushort u3);
	static uint TSCIIToUnicode(uint code, uint *s);

#define IsTSCIIChar(c)        (((c) >= 0x80) && ((c) <= 0xfd))

	TsciiCodec::~TsciiCodec()
	{
	}
	
	string TsciiCodec::convertFromUnicode(const ushort *uc, int len, ConverterState *state) const
	{
		char replacement = '?';
		if (state) {
			if (state->flags & ConvertInvalidToNull)
				replacement = 0;
		}
		int invalid = 0;

		std::vector<char> rstr(len+1);
		rstr[len] = '\0';
		uchar* cursor = (uchar*)rstr.data();
		for (int i = 0; i < len; i++) {
			ushort ch = uc[i];
			uchar j;
			if (UCS2Tool::row(ch) == 0x00 && UCS2Tool::cell(ch) < 0x80) {
				// ASCII
				j = UCS2Tool::cell(ch);
			} else if ((j = UnicodeToTSCII(uc[i],
											  uc[i + 1],
											  uc[i + 2]))) {
				// We have to check the combined chars first!
				i += 2;
			} else if ((j = UnicodeToTSCII(uc[i],
											  uc[i + 1], 0))) {
				i++;
			} else if ((j = UnicodeToTSCII(uc[i], 0, 0))) {
			} else {
				// Error
				j = replacement;
				++invalid;
			}
			*cursor++ = j;
		}
		string rstr_str(rstr.data(),cursor - (const uchar*)rstr.data());

		if (state) {
			state->invalidChars += invalid;
		}
		return rstr_str;
	}

	u16string TsciiCodec::convertToUnicode(const char* chars, int len, ConverterState *state) const
	{
		ushort replacement = SpecialCharacter::ReplacementCharacter;
		if (state) {
			if (state->flags & ConvertInvalidToNull)
				replacement = SpecialCharacter::Null;
		}
		int invalid = 0;

		u16string result;
		for (int i = 0; i < len; i++) {
			uchar ch = chars[i];
			if (ch < 0x80) {
				// ASCII
				result += char(ch);
			} else if (IsTSCIIChar(ch)) {
				// TSCII
				uint s[3];
				uint u = TSCIIToUnicode(ch, s);
				uint *p = s;
				while (u--) {
					uint c = *p++;
					if (c)
						result += ushort(c);
					else {
						result += replacement;
						++invalid;
					}
				}
			} else {
				// Invalid
				result += replacement;
				++invalid;
			}
		}

		if (state) {
			state->invalidChars += invalid;
		}
		return result;
	}

	string TsciiCodec::name() const
	{
		return "TSCII";
	}

	int TsciiCodec::mibEnum() const
	{
	  return 2107;
	}

	static const int UnToTsLast = 124; // 125 items -- so the last will be 124
	static const ushort UnToTs [][4] = {
		// *Sorted* list of TSCII maping for unicode chars
		//FIRST  SECOND  THIRD   TSCII
		{0x00A0, 0x0000, 0x0000, 0xA0},
		{0x00A9, 0x0000, 0x0000, 0xA9},
		{0x0B83, 0x0000, 0x0000, 0xB7},
		{0x0B85, 0x0000, 0x0000, 0xAB},
		{0x0B86, 0x0000, 0x0000, 0xAC},
		{0x0B87, 0x0000, 0x0000, 0xAD},
		{0x0B88, 0x0000, 0x0000, 0xAE},
		{0x0B89, 0x0000, 0x0000, 0xAF},
		{0x0B8A, 0x0000, 0x0000, 0xB0},
		{0x0B8E, 0x0000, 0x0000, 0xB1},
		{0x0B8F, 0x0000, 0x0000, 0xB2},
		{0x0B90, 0x0000, 0x0000, 0xB3},
		{0x0B92, 0x0000, 0x0000, 0xB4},
		{0x0B93, 0x0000, 0x0000, 0xB5},
		{0x0B94, 0x0000, 0x0000, 0xB6},
		{0x0B95, 0x0000, 0x0000, 0xB8},
		{0x0B95, 0x0B82, 0x0000, 0xEC},
		{0x0B95, 0x0BC1, 0x0000, 0xCC},
		{0x0B95, 0x0BC2, 0x0000, 0xDC},
		{0x0B99, 0x0000, 0x0000, 0xB9},
		{0x0B99, 0x0B82, 0x0000, 0xED},
		{0x0B99, 0x0BC1, 0x0000, 0x99},
		{0x0B99, 0x0BC2, 0x0000, 0x9B},
		{0x0B9A, 0x0000, 0x0000, 0xBA},
		{0x0B9A, 0x0B82, 0x0000, 0xEE},
		{0x0B9A, 0x0BC1, 0x0000, 0xCD},
		{0x0B9A, 0x0BC2, 0x0000, 0xDD},
		{0x0B9C, 0x0000, 0x0000, 0x83},
		{0x0B9C, 0x0B82, 0x0000, 0x88},
		{0x0B9E, 0x0000, 0x0000, 0xBB},
		{0x0B9E, 0x0B82, 0x0000, 0xEF},
		{0x0B9E, 0x0BC1, 0x0000, 0x9A},
		{0x0B9E, 0x0BC2, 0x0000, 0x9C},
		{0x0B9F, 0x0000, 0x0000, 0xBC},
		{0x0B9F, 0x0B82, 0x0000, 0xF0},
		{0x0B9F, 0x0BBF, 0x0000, 0xCA},
		{0x0B9F, 0x0BC0, 0x0000, 0xCB},
		{0x0B9F, 0x0BC1, 0x0000, 0xCE},
		{0x0B9F, 0x0BC2, 0x0000, 0xDE},
		{0x0BA1, 0x0B82, 0x0000, 0xF2},
		{0x0BA3, 0x0000, 0x0000, 0xBD},
		{0x0BA3, 0x0B82, 0x0000, 0xF1},
		{0x0BA3, 0x0BC1, 0x0000, 0xCF},
		{0x0BA3, 0x0BC2, 0x0000, 0xDF},
		{0x0BA4, 0x0000, 0x0000, 0xBE},
		{0x0BA4, 0x0BC1, 0x0000, 0xD0},
		{0x0BA4, 0x0BC2, 0x0000, 0xE0},
		{0x0BA8, 0x0000, 0x0000, 0xBF},
		{0x0BA8, 0x0B82, 0x0000, 0xF3},
		{0x0BA8, 0x0BC1, 0x0000, 0xD1},
		{0x0BA8, 0x0BC2, 0x0000, 0xE1},
		{0x0BA9, 0x0000, 0x0000, 0xC9},
		{0x0BA9, 0x0B82, 0x0000, 0xFD},
		{0x0BA9, 0x0BC1, 0x0000, 0xDB},
		{0x0BA9, 0x0BC2, 0x0000, 0xEB},
		{0x0BAA, 0x0000, 0x0000, 0xC0},
		{0x0BAA, 0x0B82, 0x0000, 0xF4},
		{0x0BAA, 0x0BC1, 0x0000, 0xD2},
		{0x0BAA, 0x0BC2, 0x0000, 0xE2},
		{0x0BAE, 0x0000, 0x0000, 0xC1},
		{0x0BAE, 0x0B82, 0x0000, 0xF5},
		{0x0BAE, 0x0BC1, 0x0000, 0xD3},
		{0x0BAE, 0x0BC2, 0x0000, 0xE3},
		{0x0BAF, 0x0000, 0x0000, 0xC2},
		{0x0BAF, 0x0B82, 0x0000, 0xF6},
		{0x0BAF, 0x0BC1, 0x0000, 0xD4},
		{0x0BAF, 0x0BC2, 0x0000, 0xE4},
		{0x0BB0, 0x0000, 0x0000, 0xC3},
		{0x0BB0, 0x0B82, 0x0000, 0xF7},
		{0x0BB0, 0x0BC1, 0x0000, 0xD5},
		{0x0BB0, 0x0BC2, 0x0000, 0xE5},
		{0x0BB1, 0x0000, 0x0000, 0xC8},
		{0x0BB1, 0x0B82, 0x0000, 0xFC},
		{0x0BB1, 0x0BC1, 0x0000, 0xDA},
		{0x0BB1, 0x0BC2, 0x0000, 0xEA},
		{0x0BB2, 0x0000, 0x0000, 0xC4},
		{0x0BB2, 0x0B82, 0x0000, 0xF8},
		{0x0BB2, 0x0BC1, 0x0000, 0xD6},
		{0x0BB2, 0x0BC2, 0x0000, 0xE6},
		{0x0BB3, 0x0000, 0x0000, 0xC7},
		{0x0BB3, 0x0B82, 0x0000, 0xFB},
		{0x0BB3, 0x0BC1, 0x0000, 0xD9},
		{0x0BB3, 0x0BC2, 0x0000, 0xE9},
		{0x0BB4, 0x0000, 0x0000, 0xC6},
		{0x0BB4, 0x0B82, 0x0000, 0xFA},
		{0x0BB4, 0x0BC1, 0x0000, 0xD8},
		{0x0BB4, 0x0BC2, 0x0000, 0xE8},
		{0x0BB5, 0x0000, 0x0000, 0xC5},
		{0x0BB5, 0x0B82, 0x0000, 0xF9},
		{0x0BB5, 0x0BC1, 0x0000, 0xD7},
		{0x0BB5, 0x0BC2, 0x0000, 0xE7},
		{0x0BB7, 0x0000, 0x0000, 0x84},
		{0x0BB7, 0x0B82, 0x0000, 0x89},
		{0x0BB8, 0x0000, 0x0000, 0x85},
		{0x0BB8, 0x0B82, 0x0000, 0x8A},
		{0x0BB9, 0x0000, 0x0000, 0x86},
		{0x0BB9, 0x0B82, 0x0000, 0x8B},
		{0x0BBE, 0x0000, 0x0000, 0xA1},
		{0x0BBF, 0x0000, 0x0000, 0xA2},
		{0x0BC0, 0x0000, 0x0000, 0xA3},
		{0x0BC1, 0x0000, 0x0000, 0xA4},
		{0x0BC2, 0x0000, 0x0000, 0xA5},
		{0x0BC6, 0x0000, 0x0000, 0xA6},
		{0x0BC7, 0x0000, 0x0000, 0xA7},
		{0x0BC8, 0x0000, 0x0000, 0xA8},
		{0x0BCC, 0x0000, 0x0000, 0xAA},
		{0x0BE6, 0x0000, 0x0000, 0x80},
		{0x0BE7, 0x0000, 0x0000, 0x81},
		{0x0BE7, 0x0BB7, 0x0000, 0x87},
		{0x0BE7, 0x0BB7, 0x0B82, 0x8C},
		{0x0BE8, 0x0000, 0x0000, 0x8D},
		{0x0BE9, 0x0000, 0x0000, 0x8E},
		{0x0BEA, 0x0000, 0x0000, 0x8F},
		{0x0BEB, 0x0000, 0x0000, 0x90},
		{0x0BEC, 0x0000, 0x0000, 0x95},
		{0x0BED, 0x0000, 0x0000, 0x96},
		{0x0BEE, 0x0000, 0x0000, 0x97},
		{0x0BEF, 0x0000, 0x0000, 0x98},
		{0x0BF0, 0x0000, 0x0000, 0x9D},
		{0x0BF1, 0x0000, 0x0000, 0x9E},
		{0x0BF2, 0x0000, 0x0000, 0x9F},
		{0x2018, 0x0000, 0x0000, 0x91},
		{0x2019, 0x0000, 0x0000, 0x92},
		{0x201C, 0x0000, 0x0000, 0x93},
		{0x201C, 0x0000, 0x0000, 0x94}
	};

	static const ushort TsToUn [][3] = {
		// Starting at 0x80
		{0x0BE6, 0x0000, 0x0000},
		{0x0BE7, 0x0000, 0x0000},
		{0x0000, 0x0000, 0x0000}, // unknown
		{0x0B9C, 0x0000, 0x0000},
		{0x0BB7, 0x0000, 0x0000},
		{0x0BB8, 0x0000, 0x0000},
		{0x0BB9, 0x0000, 0x0000},
		{0x0BE7, 0x0BB7, 0x0000},
		{0x0B9C, 0x0B82, 0x0000},
		{0x0BB7, 0x0B82, 0x0000},
		{0x0BB8, 0x0B82, 0x0000},
		{0x0BB9, 0x0B82, 0x0000},
		{0x0BE7, 0x0BB7, 0x0B82},
		{0x0BE8, 0x0000, 0x0000},
		{0x0BE9, 0x0000, 0x0000},
		{0x0BEA, 0x0000, 0x0000},
		{0x0BEB, 0x0000, 0x0000},
		{0x2018, 0x0000, 0x0000},
		{0x2019, 0x0000, 0x0000},
		{0x201C, 0x0000, 0x0000},
		{0x201C, 0x0000, 0x0000}, // two of the same??
		{0x0BEC, 0x0000, 0x0000},
		{0x0BED, 0x0000, 0x0000},
		{0x0BEE, 0x0000, 0x0000},
		{0x0BEF, 0x0000, 0x0000},
		{0x0B99, 0x0BC1, 0x0000},
		{0x0B9E, 0x0BC1, 0x0000},
		{0x0B99, 0x0BC2, 0x0000},
		{0x0B9E, 0x0BC2, 0x0000},
		{0x0BF0, 0x0000, 0x0000},
		{0x0BF1, 0x0000, 0x0000},
		{0x0BF2, 0x0000, 0x0000},
		{0x00A0, 0x0000, 0x0000},
		{0x0BBE, 0x0000, 0x0000},
		{0x0BBF, 0x0000, 0x0000},
		{0x0BC0, 0x0000, 0x0000},
		{0x0BC1, 0x0000, 0x0000},
		{0x0BC2, 0x0000, 0x0000},
		{0x0BC6, 0x0000, 0x0000},
		{0x0BC7, 0x0000, 0x0000},
		{0x0BC8, 0x0000, 0x0000},
		{0x00A9, 0x0000, 0x0000},
		{0x0BCC, 0x0000, 0x0000},
		{0x0B85, 0x0000, 0x0000},
		{0x0B86, 0x0000, 0x0000},
		{0x0B87, 0x0000, 0x0000},
		{0x0B88, 0x0000, 0x0000},
		{0x0B89, 0x0000, 0x0000},
		{0x0B8A, 0x0000, 0x0000},
		{0x0B8E, 0x0000, 0x0000},
		{0x0B8F, 0x0000, 0x0000},
		{0x0B90, 0x0000, 0x0000},
		{0x0B92, 0x0000, 0x0000},
		{0x0B93, 0x0000, 0x0000},
		{0x0B94, 0x0000, 0x0000},
		{0x0B83, 0x0000, 0x0000},
		{0x0B95, 0x0000, 0x0000},
		{0x0B99, 0x0000, 0x0000},
		{0x0B9A, 0x0000, 0x0000},
		{0x0B9E, 0x0000, 0x0000},
		{0x0B9F, 0x0000, 0x0000},
		{0x0BA3, 0x0000, 0x0000},
		{0x0BA4, 0x0000, 0x0000},
		{0x0BA8, 0x0000, 0x0000},
		{0x0BAA, 0x0000, 0x0000},
		{0x0BAE, 0x0000, 0x0000},
		{0x0BAF, 0x0000, 0x0000},
		{0x0BB0, 0x0000, 0x0000},
		{0x0BB2, 0x0000, 0x0000},
		{0x0BB5, 0x0000, 0x0000},
		{0x0BB4, 0x0000, 0x0000},
		{0x0BB3, 0x0000, 0x0000},
		{0x0BB1, 0x0000, 0x0000},
		{0x0BA9, 0x0000, 0x0000},
		{0x0B9F, 0x0BBF, 0x0000},
		{0x0B9F, 0x0BC0, 0x0000},
		{0x0B95, 0x0BC1, 0x0000},
		{0x0B9A, 0x0BC1, 0x0000},
		{0x0B9F, 0x0BC1, 0x0000},
		{0x0BA3, 0x0BC1, 0x0000},
		{0x0BA4, 0x0BC1, 0x0000},
		{0x0BA8, 0x0BC1, 0x0000},
		{0x0BAA, 0x0BC1, 0x0000},
		{0x0BAE, 0x0BC1, 0x0000},
		{0x0BAF, 0x0BC1, 0x0000},
		{0x0BB0, 0x0BC1, 0x0000},
		{0x0BB2, 0x0BC1, 0x0000},
		{0x0BB5, 0x0BC1, 0x0000},
		{0x0BB4, 0x0BC1, 0x0000},
		{0x0BB3, 0x0BC1, 0x0000},
		{0x0BB1, 0x0BC1, 0x0000},
		{0x0BA9, 0x0BC1, 0x0000},
		{0x0B95, 0x0BC2, 0x0000},
		{0x0B9A, 0x0BC2, 0x0000},
		{0x0B9F, 0x0BC2, 0x0000},
		{0x0BA3, 0x0BC2, 0x0000},
		{0x0BA4, 0x0BC2, 0x0000},
		{0x0BA8, 0x0BC2, 0x0000},
		{0x0BAA, 0x0BC2, 0x0000},
		{0x0BAE, 0x0BC2, 0x0000},
		{0x0BAF, 0x0BC2, 0x0000},
		{0x0BB0, 0x0BC2, 0x0000},
		{0x0BB2, 0x0BC2, 0x0000},
		{0x0BB5, 0x0BC2, 0x0000},
		{0x0BB4, 0x0BC2, 0x0000},
		{0x0BB3, 0x0BC2, 0x0000},
		{0x0BB1, 0x0BC2, 0x0000},
		{0x0BA9, 0x0BC2, 0x0000},
		{0x0B95, 0x0B82, 0x0000},
		{0x0B99, 0x0B82, 0x0000},
		{0x0B9A, 0x0B82, 0x0000},
		{0x0B9E, 0x0B82, 0x0000},
		{0x0B9F, 0x0B82, 0x0000},
		{0x0BA3, 0x0B82, 0x0000},
		{0x0BA1, 0x0B82, 0x0000},
		{0x0BA8, 0x0B82, 0x0000},
		{0x0BAA, 0x0B82, 0x0000},
		{0x0BAE, 0x0B82, 0x0000},
		{0x0BAF, 0x0B82, 0x0000},
		{0x0BB0, 0x0B82, 0x0000},
		{0x0BB2, 0x0B82, 0x0000},
		{0x0BB5, 0x0B82, 0x0000},
		{0x0BB4, 0x0B82, 0x0000},
		{0x0BB3, 0x0B82, 0x0000},
		{0x0BB1, 0x0B82, 0x0000},
		{0x0BA9, 0x0B82, 0x0000}
	};

	static int cmp(const ushort *s1, const ushort *s2, size_t len)
	{
		int diff = 0;

		while (len-- && (diff = *s1++ - *s2++) == 0)
			;

		return diff;
	}

	static uchar UnicodeToTSCII(ushort u1, ushort u2, ushort u3)
	{
		ushort s[3];
		s[0] = u1;
		s[1] = u2;
		s[2] = u3;

		int a = 0;  // start pos
		int b = UnToTsLast; // end pos

		// do a binary search for the composed unicode in the list
		while (a <= b) {
			int w = (a + b) / 2;
			int j = cmp(UnToTs[w], s, 3);

			if (j == 0)
				// found it
				return UnToTs[w][3];

			if (j < 0)
				a = w + 1;
			else
				b = w - 1;
		}

		return 0;
	}

	static unsigned int TSCIIToUnicode(uint code, uint *s)
	{
		int len = 0;
		for (int i = 0; i < 3; i++) {
			uint u = TsToUn[code & 0x7f][i];
			s[i] = u;
			if (s[i]) len = i + 1;
		}

		return len;
	}
}